Sheryl Ubelacker, The Canadian Press
Published Tuesday, March 24, 2015 9:08PM EDT

TORONTO -- When Angelina Jolie revealed two years ago that she'd had a double mastectomy to prevent hereditary breast cancer, there was a huge jump in the number of women seeking testing for the genetic mutation that put the actress at risk.

With Jolie's announcement Tuesday that she had her ovaries and fallopian tubes removed to prevent ovarian cancer related to the BRCA genetic mutation, some experts suggested the so-called "Angelina effect" may again spur more women to investigate their own risk for ovarian cancer -- especially those who know they carry the faulty gene.

Jolie, 39, learned two years ago that she carries a defective BRCA1 gene, which significantly elevates the risk for both breast and ovarian cancer. Her mother died of ovarian cancer and her maternal grandmother also had the disease.

BRCA1 and BRCA2 mutations -- BRCA stands for breast cancer susceptibility gene -- are most commonly found in women of Ashkenazi Jewish descent, although some northern European populations also have a higher risk of inheriting one of the mutated genes. Carriers are about five times more likely to get breast cancer.

In a New York Times op-ed article, Jolie said that having the genetic anomaly does not mean an automatic "leap to surgery" -- other medical options were possible. But her family history tipped the balance in favour of the operation.

The surgery puts a woman in menopause and Jolie said she's now taking hormones.

Kelly Metcalfe, a researcher at Women's College Hospital in Toronto, said it's strongly recommended that women with a BRCA1 or BRCA2 mutation have their ovaries and fallopian tubes removed at age 35 to 40, or when child-bearing is finished, to prevent ovarian cancer.

While screening programs like mammography can detect breast cancers early, leading to good survival rates, that isn't the case for ovarian cancer, she said.

"We don't have good screening. The majority of ovarian cancers are picked up at a late stage, and at that late stage the survival rates are low," said Metcalfe, noting that only about 45 per cent of women live five years after diagnosis.

"So we want to avoid that happening with women who we know are at high risk of developing the disease."

A 2014 study she helped conduct found women with BRCA-related breast cancer who had a double mastectomy were half as likely to die of the disease within 20 years compared to those who opted for removal of only the cancerous breast.

"There's not very many things we can do in life to reduce your risk of dying by that much," said Metcalfe.

"And that's why we recommend the surgery to BRCA1 or BRCA2 carriers. We don't think they need to get ovarian cancer. We don't want them to get ovarian cancer because the survival rates are so low."

She said about two-thirds of BRCA-affected women elect to have the surgery, called a bilateral salpingo-oophorectomy.

Dr. Andrea Eisen, head of the Familial Cancer Program at Sunnybrook Health Sciences Centre in Toronto, was involved in a study of the Angelina effect in 2014.

She compared referrals for genetic testing by high-risk women six months before and six months after Jolie made her mastectomy public.

Researchers found referral rates almost doubled. And the Hollywood star's story had motivated the right kind of patients to seek genetic testing and counselling -- those who were most likely to be at risk for one or both of the mutations.

The Angelina effect may be less significant this time, Eisen said, as the focus of Jolie's current article isn't about encouraging at-risk women to find out if they're BRCA carriers. It's aimed at women who know they are carriers and how they might mitigate their risk of ovarian cancer.

"I'm not sure we'll see the same traction," said Eisen, who nevertheless plans to do a followup study to see if Jolie's awareness-raising story once again influences referral rates.